CPT code 99183: Hyperbaric oxygen, professional service2026 Medicare rate & RVUs in Washington
Reports the physician’s professional service for a hyperbaric oxygen treatment session, separately from the technical service for chamber treatment.
Medicare pays $110.07–$118.68 for 99183 in the office in Washington, from Rest of Washington to King County, WA. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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On this page 9 sections
What 99183 covers
Code 99183 represents the physician’s professional involvement in a hyperbaric oxygen treatment session. In a hospital or outpatient wound-care setting, the physician oversees the patient during treatment and documents the clinical assessment and response. Common treatment situations include selected diabetic lower-extremity wounds and tissue injury from radiation; the code represents the professional service, not the chamber or oxygen equipment.
Report the code for each documented session in which the physician provides the professional service. The record should identify the treatment session, the patient’s condition and relevant assessment, and the physician’s oversight and report. CMS identifies 99183 as a professional-component-only code; the technical portion is represented separately, commonly by HCPCS G0277 for hyperbaric oxygen under pressure in a full-body chamber. Keep documentation and claims distinct so the professional service is not mistaken for the chamber’s technical service.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where 99183 pays more and less in Washington
| Payment locality | Office | Facility |
|---|---|---|
| King County, WA | $118.68 | $118.68 |
| Rest of Washington | $110.07 | $110.07 |
How the 99183 rate is calculated
Each of 99183’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 99183
RVUs × geographic indexes × conversion factor
Work2.06
2.06 RVUs× 1.000 GPCI
Practice expense0.96
0.96 RVUs× 1.000 GPCI
Malpractice0.26
0.26 RVUs× 1.000 GPCI
Adjusted RVUs
3.2800
Conversion factor
$33.4009
Medicare rate
$109.55
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 99183
The CMS indicators that decide how 99183 is paid alongside other services.
CMS payment indicators · 99183
Hyperbaric oxygen, professional service
| Rule | CMS value | What it means |
|---|---|---|
| Global period | XXX | The global surgery concept doesn’t apply. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 2 | Professional component only. |
99183 compared with similar codes
Compare codes · National
99183 vs G0277: Medicare rates
How to choose
- G0277Hyperbaric oxygenFull-body chamber, per 30 minutes
- 99183 represents the physician’s professional service; G0277 represents the technical hyperbaric chamber service, measured in 30-minute units.
99183 billing questions
Does 99183 include the hyperbaric chamber service?
No. CMS identifies 99183 as professional-component-only; the chamber’s technical service is reported separately, commonly with HCPCS G0277.
What should the physician document for 99183?
Document the treatment session, the patient’s condition and assessment, and the physician’s oversight and report for that session.
Is 99183 reported once per course of therapy or per session?
It represents a treatment session, so report it for each session when the physician provides and documents the professional service.
Should modifier 26 be appended to 99183?
CMS identifies 99183 itself as a professional-component-only code. Do not treat it as the technical chamber service.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
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